Okay, so I created a patch to fix this issue. Go easy on me since thisis my first patch to Emacs ;)

The changes are pretty simple:

- `eshell-exit-success-p' has been changed to only check if the last exit code was zero, rather than first checking whether the last command returned nil.- `eshell-exec-lisp' has been changed so that it will set `eshell-last-command-status' to 1 if it catches an error.- These changes together make it so that the `&&' operator in Eshell behaves more expectedly to someone who has used a bash-like shell and so that other things involving the success of Lisp commands in Eshell are more reliable.Feel free to point out anything else that should be done here or anyerrors on my part. I have tested these changes out and everything seemsokay. I can run the aforementioned commands that were problematic. Examples: